Rivet



Patented July 31, 1951 UNITED STATES PATENT OFFICE 4 Claims. (cuss- 40 The invention relates to rivets and especially to rivets suitable for double walls of structures. In airplane structures such, for example,v as wings having double coverings or an inner and an outer skin or wall of thin sheet almninum in 5 spaced-apart relation to one another and with a hollow space 'therebetween, it. is difiicult to fixedly secure such inner and outer skins to one another and to adjacent parts, especially where.

blind riveting must be resorted. to, i. e.,. where' only one side of the double Wall or skin is available for operations. It is also difilcul-t' to maimtain permanently the inner and-'- outer skins. in such spaced-apart relation substantially uniformly throughout their entire extent especially under the distorting action of load and other.. stresses on such structures and air pressure differentials which may exist at the double wall. The invention is applicable especially" for such constructions and for such purposes but is not necessarily limited thereto.

Objects of the invention are to provide anim proved hollow rivet; to provide for engaging a- Wall at a plurality of positions in spaced-apart series along the rivet; to provide for outwardly collapsing the wall of the rivet at such plurality of positions; to provide for such collapsing of the rivet by operations from one side only of the wall and preferably in a sequential manner relative to said side of the Wall; to provide for maintain- 301 mg the spacing of the parts of a d'ouble'wall construction and for strengthening such double Wallconstruction, especially to resist distortion; to provide for fixedly securing such wall parts together in spaced-relationship and forretaining tion,v convenience of manufacture and ihstalla- 40 tion, and for effectiveness of operation.

Other objects of the invention are to provide substantially fluid-tight attachments onthe d011- ble walls of structures; and" to provide an attachment in which abody can be detachablymounted" on such walls by a screw member leaving the walls substantially water-tight and even airtight and. especially whether'the body and screw-- member be mounted or removed.

These and further objects and advantages will be apparent from the following description, ref-, erence being had co-the accompanying drawingin'which: g

Fig. 1 is a plan view of ad'oubl'ewall construc-.

tion having improved hollow rivets constructed I in accordance with; and. embodying theinvention,

parts being broken away;

Fig. 2 is a section taken. along line 2-2 of. Fig. 1;

Fig. 3' is a Perspective view of the improved rivet before assembly with thewall;

Fig. 4: is a longitudinal sectional view of. the rivet; and: i

Fig. 5 is a longitudinal sectional view of a modified construction of the rivet.

In the illustrative construction. shown inl; a plurality of rivets: l0,; Hi embodying the invention are disposed in. spaced-apart relationship in a wall H of: double construction having aligned. apertures. i2, F3 for receiving. such rivets 10;. H1. The wallll may be a component of an airplane structure such, for example. as the covering. of a wing having inner t4 andan outer i5 skin. of thin sheet aluminum or other suitable lightweight relatively stilt sheet material in spaced-.- apart relation: to one another with. a. hollow space therebetweenproviding. the desired doublewallconstructiona For the arrangement shown, the improved rivets Ill I fl'not only function asspacing means to maintainipermanently'the inner and. outer skins l4 and I5 in the desired substantially uniformly spaced-apart relation substantially throughout their extent. but also function to secure and hold fixedly together such inner and outer skins or wall parts together in such spaced.- apart relationship while so; maintaining and. securing such. parts in a. substantially fluid-tight manner- Each rivet [-0 is preferably of a. light, strong ductile material such as-aluminumv although. it may beof copper, steel. or other suitable alloy. Preferably,v the rivet Ills-comprises a cylindrical and. tubular body 16- having desirably a flange I1 at one end thereof; for. seating againsta. face such-,. for example, as the outer skin l5v of the wall ll-.. The body I6 is of the desired. length and has a bore l9 extending. therethrough from the flange IJIv and: terminating at an opposite end portion 20 of the rivet, the bore: l 9 beingdefined by an. annular and continuous wall, as shown especially in Figs. 2', 3 and 4. Such. wall. of the rivet i It includes a pair of. spaced-apart outwardlycol'lapsible portions 2|, 22 in. series along. the cylindrical body for engaging the inner and outer skins l4 and [5, respectively. The outwardly-collapsible cylindrical. portions 2|; 22 are interconnected. by an internally-threaded intermediate portion 25' extending. between; adjacent sides 23, 24- of the collapsible portions 21:, 22 and engageab'lei withza screw member (not shown)' inserted in the bore of the rivet from the flanged end thereof. This facilitates the application of axial pressure with circumferential uniformity by virtue of the threaded connection at the intermediate portion 25 for outwardly collapsing the portion 2| which assures uniform pressure application entirely around the rivet by the screw-member used for collapsing the rivet. The end portion extends from the other side of the collapsible portion 22 and is also internally threaded for facilitating collapsing the portion 22 by the application of substantially circumferentially uniform and endwise pressure by a second screw member (not shown) similarly inserted in the bore of the rivet. The cylindrical form of the outwardly-collapsible portions 2|, 22 of the rivet gives maximum material in the bulged or substantially folded regions of the expanded rivet for maximum holding strength and substantial water-tightness of the joint. 7

The wall of the rivet H! at the respective outwardly-collapsible portions 2|, 22 may be of the same or different thickness but such wall at each such portions is of lesser radial thickness than that at the intermediate portion and desirably the end portion 20, and the provision of such reduced wall thickness may be accomplished by having the bore IQ of a different diameter at each of the wall portions 20, 2|, 22 and 25. To this end, the rivet may have a counterbore extending from the flanged end throughout the extent of the portion 2| to the side 23 thereof and may also have at the portion 22 a counterbore of lesser diameter than that at the first said portion 2|, as shown especially in Fig. 4. The bore l9 at the internally threaded intermediate portion 25 is desirably of greater diameter than that at the end portion 20 and of the same or lesser diameter than that of the counterbore at the portion 22 for facilitating th free passage of the screw member through the portions 22, 25 for engaging the end portion 20 to collapse the outwardly-collapsible portion 22 in sequence after the first collapsible portion 2| has been expanded in a substantially folded manner, as shown especially in Fig. 2.

The body l6 throughout the extent of the first collapsible portion 2| and the intermediate portion 25 is desirably of substantially uniform and of greater external diameter as compared to the substantially uniform and external diameter thereof at the other collapsible portion 22 and the end portion 20. Such arrangement facilitates the provision of a backing shoulder 26 having desirably a flat seating face intermediate the ends of the rivet ID at the junction of the respective portions 22 and 25, which shoulder assures backing support of the thin inner skin l4 of-the wall during the collapsing operations of the aforesaid other collapsible portion 22 and further functions to assure the desired spacing between the inner and outer skins l4 and I5.

In assembling the rivet ID with the skins l4 and i5, the rivet is threadedly engaged at the intermediate portion 25 with the screw member of a suitable tool such, for example, as shown in Patent 2,149,199 to Harry E. Waner. The rivet is then inserted through the registering apertures l2, l3 in the inner and outer skins |4, |5 such that the flange I1 is seated against the outer skin l5 and the shoulder 26 is seated against the inner skin I4. The rivet l0 may then be shortened by axial pressure applied at the intermediate portion as as to collapse the outwardly-collapsible portion 2| in a substantially folded manner, as shown especially in Fig. 2 at 21, thereby forming a flange on each side of the outer skin l5. The screw member of the tool is then removed and a second screw member of lesser diameter is inserted in the bore |9 from the flanged end. Such second member passes freely through the bore at the intermediate and collapsible portions 22, 25 and is threadedly engaged with the end portion 20. The other outwardly collapsible portion 22 is then expanded by the application of axial endwise pressure at the end portion 20 by means of such second screw member, the backing shoulder 25 functioning to provide substantially circumferentially uniform support for the inner skin l4 during the expanding of the portion 22 thereby effectively resisting inward localized distortion of the inner skin l4 toward the outer skin IS.

The sequential shortening of the rivet by axial pressure applied at the means on either side of the collapsible portions 2|, 22 adapted to cooperate with the tool, such means comprising the flange H, the intermediate portion 25 and the end portion 20, as described hereinabove, is shown especially in Fig. 2 at 21, 28 and 29. The condition of the rivet upon completion of the first phase of the shortening operation is shown at 21 and upon completion of both phases at 28 and 29. It will be noted that the condition shown at 23 illustrates clearly the outwardly-extending folds in the wall of the rivet at the respective collapsible portions 2 22 engaging the inner and outer skins I4, I 5.

The rivet construction thus advantageously provides for uniting and maintaining the inner and outer skins |4, |5 in the desired spaced-apart relationship and materially strengthens the wall against substantial distortion by a bracing strut action. It also advantageously assures the desired spacing between the inner and outer skins while effectively resisting localized distortion of the thin metal skins during the blind riveting operations. An additional advantage is that the attachment of other structural parts of the airplane directly to the wing skin'in a substantially fluid-tight manner is facilitated inasmuch as screw fasteners threadedly engaging preferably the intermediate portion 25 of the rivet may be used for such purposes.

If desired, the end portion 20 of the rivet l0 may be completely closed in the manner of the modified construction illustrated especially in Fig. 5, whereby a substantially fluid-tight attachment is assured whether the other part of the airplane structure and screw fastener be mounted or removed relative to the wing.

It is to be understood that in addition to functioning as a spacing and stiffening means for the double skin covering of the wing, that the rivet may be used for attaching securely such wing covering to adjacent structure of the wing or other aircraft part and for other like attaching purposes. The rivet I0 is also applicable to relatively thick walls of substantially solid, or multiply, or both constructions, especially those constructions having a facing or facings of relatively stiff sheet material such as metal, plastic, glass, plywood, and other like materials at one or both sides of the walls for facilitating engagement with the wall at one or both collapsible portions of the rivet substantially in the manner shown in Figs.

, 1 to 4. In the case of such solid of multi-ply walls,

if desired, the rivet at its end portion 2|! need not project beyond the wall and the collapsible portion 22, which is relatively remote from the flange may, if desired, be expanded outwardly intmthematerial of the solid wall for facilitatin semire attachment or: the rivet to the walk at spaced-apart zones al'ongi the rivet;

modified constructionfi dot the rivetshown Figr is useful for the-convenient attachment inxhollbw'walls; andiisparticularly suited; for-solid multieply wall applications;- since: therivet: 3.0 eliminates the:necessity of a wall. aperture ofrtwo difierentl'diameters as in thecase of rivet; 1:0 and maybe sequentially shortened. using; a. single screvwmember for; the. tool. The. arrangement: is also suclr that the screw' fastener for detaehably a. body" to; the. wall may be threadedly engagedi along: a. relatively greater: extent: of: .the rivet 30535; comparedl toy that of the rivet: I111.

' 'lZo these: ends, the rivet 30: wmchrmayhe; of dlictiie material like; that of; the'riveir till cormprises. a"; cylindrical; body 3|; at substantially" uni,- form: diameter throughout its extent; having a flange:- 32: at one end for seating: against: a. face oil the. wall-:and: a: bore: 33. theneirr'extendifrom the; flanged end? and: terminating ina closed:and. internally threaded. end. portiomfl defined; by'ana annular'continuouszwall. The

walk of. therivet; 30: includes: apair; of spaced! apart. ontwardly oollapsible portions; 35, -3fi1- in seriesalong, thebody'ii'lz andaan internally threadsedl intermediateportion-131:- interconnecting; the aforesaid: portions; 35;; 36-; the; closed: end; portion 3!;extending along; the; body- 3d from: the: side: 38 of the second collapsible portion: 35'.

The bore 33 is. desirably of the same substantially'uniform diameter at the intermediate portion 31 and thaclosed-vend-portionlfi and the wall of the bore at such portions 3E, 31 is internally threaded for engaging a screw member. The bore 33 is of greater diameter'at' the collapsible portions 35; 3.6, than that. at. the portions 34, 31 facilitating the provision of. walls at the outward: lye-collapsible. portions 35, 33 of. lesser radial thicknessthan that at the respective intermediate and; closed end portions. The, thickness. of; the walls: at f the outwardly-collapsible portions3'5, 361s desirably the same, althougheach suchwalls may be ofdiflerent thickness relative to. the other if desired.

. The. construction of'the rivet3llis advantageous inproviding' an attachment. in which abody can hadetachalily mounted on the wall by, a screw fastener preferably threadedly. engaged, at. both thesintermediate and the closediend portion-31, 34, although such threaded engagement may be only at the intermediate portion 31. The closed end of the body 3! further assures maintaining the wall substantially water-tight and even air tight whether the body and screw member be mounted or removed.

In assembling the rivet 30 with the wall, for example, when the wall is of double or hollow construction substantially as shown in Fig. 2, the rivet 30 is first placed in threaded engagement with the screw member of the tool and then is inserted in the registering apertures of identical diameter in the wall I I such that the flange 32 seats against one face [5 of the wall and the body 3| projects outwardly beyond the wall at the other face l4 thereof. The rivet 30 is in engagement with the screw member only at the intermediate portion 31. Such screw member under the action of the tool applies substantially uniform pressure entirely around the rivet and axially in the direction toward the flange 32 outwardly collapsing the portion 35 in asubstantially folded manner providing a flange on each side of the facing or skin l5 of the wall, the

cylindrical: form; ofthe: collapsible? portion; giving maximum. materiat in the: bulge for maximum holding and; water-tightness or the: part. The screw member is; their disengaged; with the intermediate pOlZtiDIl 3.1; and engaged witha the threadedi wall. or the closed end portionz34. The collapsible portion 362 also; collapsedjinca sub?- stairtially folded. manner-by the; application of localized distortion: during the collapsing action 7 of the portion 36.

Khan the wall is of substantially: solid or laminated'multi-ply construction with a single facing ofsuitabl'e material and is of greater thickness than the lengthof" the rivet 30, the latter under such conditions may becollapsed in the aforesaid manner; whereby theflange forme'd by-themollapsing of theportion 35' not only facilitatesclamping thefacing between such flange andithe flange 3% of the rivet but engages the material oithesolid walland theflangeprovided byflthe collapsed portion 36-also engagesthe-materi'al' of the solid" wall further assuring, holding the riveti'rr-such wall; Such construction provides the desired fluid-tight. attachment ofthe rivettothe wall and assures the strong: attach.- ment of a, body in. a detachable" manner to the wall: as by the screw fastener; in full engagement with the rivet at, its intermediate and closed end portions.

Variations, may be made without: departhig from thescope' of the invention. as: itis defined bythe. following claims. I

Iiclaimr I. A tubular rivet adapted to be inserted in. an aperture in a. structure andjupset'. by operation fronrone side only of the structure, said rivet comprisinga body having ahead; end. and; a-lbore extending from said end into. said. body, the wall of said body comprising, axially spacedeapart ontwardl collapsible portions, an 1intermediate portion separating said outwardly-collapsible portions, and an end portion beyond the outwardly-collapsible portion remote from said head end, said outwardly-collapsible portions having walls of lesser thickness than that of the intermediate and end portions so as to be bulged outwardly by forces applied axially to the rivet and transmitted axially through said intermediate and end portions to said outwardly-collapsible portions of said body, into the form of a pair of structureengaging flanges separated by said intermediate portion, and said wall of said body having means in said bore at said intermediate and end portions for detachably selectively securing said portions to an upsetting member inserted from said head end to apply the upsetting forces to said body in the axial direction thereof.

2. A tubular rivet adapted to be inserted in an aperture in a structure and upset by operation from one side only of the structure, said rivet comprising a body having a head end and a bore extending from said end into said body, the wall of said body comprising outwardly-collapsible 1 portions one of which is located adjacent said end and'the other being spaced therefrom at a position along said bore, an intermediate portion separating said outwardly-collapsible portions, and an end portion at the side of said other of the outwardly-collapsible portions remote from said head end, said outwardly-collapsible portions having continuously annular Walls of lesser thickness than that of the intermediate and end portions so as' to be bulged outwardly by forces applied axially to the rivet and transmitted axially through said intermediate and end portions to said outwardly-collapsible portions of said body, into the form of a pair of structure-engaging flanges separated by said intermediate portion, and said wall of said body being interiorly threaded at said intermediate and end portions fordetach'ably engaging an exteriorly threaded upsetting member inserted from said'head end to apply the upsetting forces to said body in the axial direction thereof.

3. A tubular rivet adapted to be inserted in an aperture in a structure and upset by operation from one side only of the structure, said rivet comprising a cylindrical body having a head at one end thereof and a cylindrical bore extending from said end into said body, the wall of said body being continuously annular and comprising outwardly-collapsible portions one of which is located adjacent said head and the other being spaced therefrom at a position along said bore, an intermediate portion extending between said outwardly-collapsible portions, and an end portion at the side of said other of the outwardlycollapsible portions remote from said head, said outwardly-collapsible portions having walls of lesser thickness than that of the intermediate and end portions so as to be bulged outwardly by forces applied axially of the rivet and transmitted axially through said intermediate and end portions to said outwardly-collapsible portions of said body, into the form of a pair of structureengagin flanges separated by said intermediate portion, and said wall of said body being interiorly threaded at said intermediate and end portions for detachably engaging an exteriorly threaded upsetting member inserted from the headed end to apply the upsetting forces to said body in the axial direction thereof.

4. A tubular rivet adapted to be seated in aligned apertures in spaced-apart work-elements and upset therein by operation from one side only of the work to maintain said work-elements in spaced-apart relation, said rivet comprising a body having a head end for engaging one of said work-elements and having a bore extending from said end into said body, the wall of said body having a stepped construction providing ou wardly-collapsible portions one of which extends from said end and the other being spaced therefrom at a position along said bore, an intermediate portion including a shoulder separating said outwardly-collapsible portions, and an end portion extending from said other of the outwardlycollapsible portions in the direction axially away from said head end, said outwardly-collapsible portions having walls of lesser thickness than that of the intermediate and end portions so as to be bulged outwardly by forces applied axially of the rivet and transmitted axially through said intermediate and end portions to said outwardly-collapsible portions of said body, into the form of a pair of work-engaging flanges separated by said intermediate portion for holding the'flrst said work-element between said head end and one of said flanges and for holding the'other workelement between said shoulder and the other flange, and the wall of said body being interiorly threaded at said intermediate and end portions for detachably engaging and exteriorly threaded upsetting member inserted from said head end to apply the upsetting forces to said body in the axial direction thereof.

ROBERT G. SELDEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Austin Nov. 20, 1945 

